You might wish to take a look at this thread. The issue that you mentioned is unlikely to be resolved soon as I have had such issues ever since I installed ESET NOD32 v4. The effects can be lessened by following some of the suggestions in that thread.

Btw, are you still using NOD32 v2, since you posted in this forum? From what the other posters have suggested, v2 doesn't seem to produce such effects, even though I haven't tried it for myself.